I can't guarantee that I got all the steps but I'll try... from the number of steps you'll see why you should let the service tech do it. ;-)

1) Stand next to car
2) Unlock car
3) Close all doors
4) Put a key in the ignition
5) Turn to accessory
6) Put remote 1 in and lock door (leave in door)
7) Allow remote 1 to rock back from the lock position (I think you leave it in this position)
8) Hold unlock button down for 10 seconds
9) Press unlock button once for remote 1
10) Repeat #7 & #8 (don't change the remote in the door)
11) Press unlock button twice for remote 2
12) Repeat again for remote 3 if you have one

This is pretty darn close to the full set of directions. I have no reason to test it out (sorry). ;-)